1. Field of the Invention
The present invention relates to a method of distributing an encoding/decoding program and a key in a security domain environment and a data divider and a data injector therefor. More particularly, the present invention relates to a method of safely distributing an encoding/decoding program and a symmetric key from a highest-level security domain to lower-level domains by dividing them using a data divider in the highest-level security domain and injecting them to an encoding/decoding device using a data injector.
2. Discussion of Related Art
In order to protect an encoding/decoding program and a key, generally, a public key is used, or a key capable of authenticating the other party's device is stored in an encoder/decoder, and a key is induced after the authentication.
The public key may be appropriately used when a plurality of keys are used. However, an encoding/decoding algorithm is asymmetrical, and requires a tremendous amount of mathematical calculations, and thus the public key may be inappropriate for real-time data processing and within a narrow-bandwidth network environment.
In the meantime, in order to store an authentication key in the encoder/decoder, the authentication key should be shared between an encoding party and a decoding party in advance. When a device of the encoding party is captured, the authentication key may be exposed due to de-capping, and may be vulnerable to a fake attack caused by a man-in-the-middle-attack.
Furthermore, within the security domain environment in which security is very highly demanded, there are at least two domains divided by security levels depending on a degree of secret, and devices included in different security domains manage confidential information according to defined regulations on actions.
Therefore, a method of safely distributing an encoding/decoding program and a related symmetric key from a device belonging to a highest-level security domain to a device belonging to a lower-level security domain is needed.